The use of magnetic fasteners is well known for various end uses and in recent years has become very popular in items such as women's handbags. However, the most popular magnetic fasteners include providing a firm engagement between the elements on the opposed surfaces which are intended to be closed and do not provide a locking mechanism. Thus, U.S. Pat. No. 5,953,795, as an example, describes a non-locking magnetic fastener in which the female assembly includes a torroidal magnetic member in which is received a ferromagnetic male member.
In recognition of the need to have a positive locking mechanism, prior workers have suggested a number of approaches, but to date, none have been widely accepted.
The present fastener is a significant improvement on the locking magnetic fasteners described in the prior art in which the locking mechanism relies upon magnetic attraction between a projecting male member and a receiving female member. Numerous variations of the prior art devices operating on this old principle have been described in the patent literature. For example, U.S. Pat. No. 5,572,772 discloses a magnetic fastener consisting of a shaped male member that includes a magnet. When the male member is inserted into the female assembly, it attracts a ferromagnetic engagement member that slides into a position that engages a portion of the male member and retains it in a locked position. The male member is released by manually displacing the engagement member from the locked position where it was held by the magnetic attractive force of the magnet. Another construction of a magnetic assembly which uses a slide lock engagement is disclosed in U.S. Pat. No. 5,868,445, in which the male assembly includes a protruding member or housing with a permanent magnet positioned inside, with an opening in the housing through which the magnet is exposed. The female assembly includes one or more ferromagnetic plates that slide into contact with the male member under the force of the magnetic attraction. In U.S. Pat. No. 5,937,487 a locking magnetic fastener having a first and second locking position is disclosed, in which the projecting male is member includes a magnet that attracts sliding members in the female assembly into contact under a recessed portion of the male member.
It is also known in the art of locking fasteners to provide assemblies and constructions in which the internal members are urged into locking engagement by a biasing force, such as a spring or other biasing member. However, such mechanisms generally require the assembly of a number of small parts that must be properly oriented, and therefore are more time-consuming and expensive to manufacture, can be less reliable and are subject to failure than a simpler construction.
As noted, non-locking magnetic fasteners are well known and generally provide a single torroidal magnet within the female with no magnet in or on the ferromagnetic male member. Various constructions of the female assembly have been suggested in which the female assembly presents a central opening in a housing that contains the magnet. A natural consequence of this arrangement is that dirt and debris can be attracted to and/or accumulate in this annular space. Thus, workers have suggested placing the magnet on or in the male member, but this also has disadvantages.
One particular disadvantage that has been found when a male assembly having a projecting permanent magnet element is employed (for example, to a ladies handbag) is that the magnetic field emanating from the part having the magnet can erase all or part of the encoded information on the magnetic strip of credit and debit cards, identification badges, and the like. This occurs when the user of the bag having a closure flap opens the fastener, reaches inside the bag with the flap still loosely overlapping the side of the handbag and withdraws the credit card, passing it in close proximity to or touching the projecting magnet containing assembly. Likewise, if the user opens the fastener with the same hand that is holding a credit card (or any other card with a magnetic strip containing digital information) when the card is being returned to the interior of the bag the magnetic strip is potentially in position to be brought into contact with, or in close proximity to the projecting male element. As a consequence, all or part of the digital data can be erased, rendering the card unusable. Another disadvantage of having permanent magnetic characteristics on the projecting male member is the potential for debris to be attracted to the male member, thereby altering its contour and thus interfering with the operation of the locking mechanism in the female assembly, which often requires the locking mechanism to function by engaging a part within the female assembly with a portion of the periphery of the sidewall of the male member.
It is therefore an object of the invention to provide an improved locking magnetic fastener in which the magnetic material is shielded and preferably resides in the female member.
It is also an object of the present invention to provide an improved locking magnetic fastener which can be constructed with only one permanent magnet in its construction, and that remains securely locked without the need for springs or other biasing members, and which can be manually unlocked with a single motion that can be accomplished with one hand.
Another object of the invention is to provide a locking magnetic fastener in which the opening in the female member is entirely or partially closed when the male member is removed to minimize the possible accumulation of debris in the interior of the female member.
It is a further object of the invention to provide a novel locking magnetic fastener that is constructed from a minimum number of parts that are themselves easily and economically fabricated with conventional tooling, and that can be quickly and simply assembled without the need for complex equipment.
Although the present invention has suitability for use in handbags and like items, it is yet another object of the invention to provide a two-part locking magnetic fastener which can be used as well for other purposes such as for maintaining drawers, doors and other closures in a secure locked relation upon engagement and which can be easily and reliably unlocked by a slide or pivot action which can, if desired, be directly or remotely activated.